Acid conc



Nov. 6 1923.

. J. PATTEN ACID CONCENTRATOR Filed sem. 7, 1918 *Y 2 Sheets-Sheel'l 1 mm /M/ I m Nov. 6, 1923.

J. PATTEN A CID CONCENTRATOR Filed Senf. '7, 1918 2 Sheets-Sheet 2 Ail() VPatented Nov. 6, 1923.

UNITED STATES PATENT OFFICE. j

JOHN PATTER, F BALTIMRE, MARYLAND.

Aoin CONCENTRATOR.

Application filed September 7, 1918. Serial No. 253,085.

To @ZZ wltomz't may concern:

Be it known that LJoI-IN Parrain, a citizen` of the United States, and residing at Baltimore, Maryland, have invented certain new and useful Improvements in Acid Concentrators, of which the following is a specification.

The present invention relates to improvements in acid concentrating apparatus of the type which comprises a series or batte-ry of connected containers through which the acid is caused to flow successively, the water being evaporated by heat supplied to the containers. In the constructions heretofore used all the surfaces in contact with the containers were lined with lead in order to protect them from the action of the acid and the steam heating coils within the container were made up from lead pipe. Necessarily the structure for mounting and supporting the linings was more or less complicated. Furthermore, repeated expansions and contractions of the lead, due to changes in temperature, in time caused buckling and cracking of the lining. Another defect resulted from the fact that acid would leak in between the linings and the shell of the lcontainer causing weakening of the shell and other troubles.

The principal object ofthis invention is to provide an apparatus in which the lead linings are eliminated and in some cases even the lead steam coils are dispensed with. To this end the container is constructed from van acid resisting material such as an alloy of iron and silicon which will be referred to hereinafter byone of its trade names, to-wit, Duriron. This is a hard, brittle sulphuric acid resisting alloy which can be used to make castings. It has considerable compressive strength but is weak in resisting tensile strains. For these reasons it has been necessary to devise a container which departs from the usual principles in making castings.

In concentrating sulphuric acid from a strength of about 50 Ba. known Yas chamber acid, up to 59 or GO'Ba. lead will resist the action of the acid if the temperature does not exceed 280o F. However, when the temperature rises to 300 F. or higher the lead is eaten away very rapidly and contaminatesand discolors the acid, as a result of which the life of the lead lined containers is very short unless the concentration is carried onv in a vacuum. Duriron, however,

will withstand the higher 'strength and temperature of the acid without being injuriously affected. But even in the cases where the lead heating coils are dispensed with and the container made from Duriron, it is easier, quicker and more economical to concentrate the acid in a vacuum for thc reason that decompositions of the acid take place at the high temperatures which are avoided when a vacuum is employed.

Other objects and features of novelty will be apparent from the description takenin connection with the drawings in which Figure 1 is a longitudinal sectional elevation through an apparatus embodying the present invention, the first and last containers being shown, it being understood that there are other similar containers interposed between these two; and.

Figure 2 is a transverse sectional elevation through one of the containers.

Referring to the drawings the numeral indicates a shell like container having its upper end open and its lower end closed by the dish-shaped bottom wall 11. This latter wall has a depending inlet nozzle 12 and an outlet nozzle 13, this latter nozzle being continued upward within the container, the upper end being open and located at an elevation to maintain the level of acid within the container at the desired height. The acid is supplied to the container through a pipe 14 which bears against the lower end of the nozzle 12, a spherical or ball and socket type of joint 15 being provided. The pipe 14; at its upper end has an inclined wall 16 which forms a trough 17 just above the joint 15 and surrounding lthe nozzle 12.

This trough is formed with a spout 18 so that acid or other fluid may be discharged into a similar trough 19 carried at the upper end of a. short length of pipe 2O which is joined to and forms a continuation of the outlet nozzle 13, a spherical'joint 21 similar to the joint 15 being provided. The pipe 2O connects with a horizontal pipe 22 `by another spherical joint 23, a trough 24 being provided around this latter joint. Thepipe 22`carries the acid to the next container where it enters ythrough a nozzle like the nozzle 12. The top of this pipe 22 is formed with a trough 25 which connects with the trough 24 and acts to carry the acid or liquid which collects therein to the troughV surrounding the inlet Vnozzle of the next container.

At its u per end the shell 10 is formed with a le ge or shoulder 26 upon which rests a ring 27 which forms a continuation of the shell lO. The lower end of this ring 27 is slightly spaced from the inner surface of the flange 28 at the top of the shell ,10. to thereby provide an annular space 29 wh1ch acts like the troughs previously mentioned. t Vitsupper end the ring 2'7 has an offset flange 30 similar to the flange 28 of the shell. A dome shaped top 31 rests on the upper end of the ring 27 and the outer periphery of the same at its lower edge is spaced from the said flange 30 to provide another trough 32. The top 31 is formed with a depending nozzle 33; and an inverted U-shaped outlet pipe 34 has one end registering with the said nozzle, a spherical joint 35 being provided between the parts. A circular flange 36 is formed near the top of the dome 31 being spaced from the outlet pipe 34 to form a trough 37 surrounding the joint 35. In the operation of the apparatus the evaporation of moisture from the acid is accompanied with a violent ebullition as a result of which considerable acid would pass out of the outlet pipe if a baffle or some other device were not interposed. In order to restrain the liquid from passing out the vapor pipe 34, a circular baffle plate 38 of less diameter than the inside of the ring 27 is arranged at the top of said ring and supported by means of the feet 39 resting on lugs 40 on the ring. This baille plate has two concentrically spaced upwardly projecting flanges 41 and 42, the upper edge of the latter flange extending up beyond the lower edge of the nozzle 33 and being spaced slightly in a radial direction therefrom. The top 31 is formed with a depending circular flange 43 which projects into the space between the flanges 41 and 42 and a similar flange 44 extends down from the top'being arranged concentric with the flange 41 and spaced radially a slight distance therefrom. It will be seen, therefore, that the passage from the interior of the ring 27 to the vapor or outlet pipe 34 is an irregular or tortuous path. Thus the vapor and entrained liquid passes around the outer periphery of the plate 38 and then weaves its way through the irregular path between the concentric flanges previously described. It will be apparent that the sudden changes in direction will soon free the vapor from any acid so that lonly substantially liquid free vapor passes out through the pipe 34. The parts thus far described are all made from an acid resisting material such as Duriron, previously mentioned As stated vthis alloy is weak tensionally and itis necessary to provide a construction in which these parts are not subjected to tensile stresses.` To this end and also for the purpose of providing a steam jacket around the shell 10, the latter is forced in against the packing 49 by the Y Vbolts 50. A similar joint 51 is provided at the upper ends of the shells 10 and 45, these joints also being made tight by a gland 52 forced against the packing 53 by the bolts 54 to make it steam tight. J ust below the joint 51 the shell 45 has an inwardly projecting ledge 55 which acts to carry the weight of the inner shell 10. It will be observed that the joint 47 is of somewhat smaller diameter than the joint 5l, the inside diameter of the ledge 55 being such that the lower end of the shell 10 will just slip by this ledge when assembling the parts. Thus the inner shell 10 is not subjected to any substantial tensile stresses because of the steam pressure within the jacket 46. At the lower end the only surface against which pressure may act in a longitudinal direction is the very slight shoulder between the joint 47 and the main part of the shell. At the upper end the only area against which steam may act to produce a tensile stress is that between the main part of the shell 10 and the ledge 55. These areas are very small and consequently the stresses produced are well within the tensile strength of the alloy.

The container is carried on posts 56 and 57, the cast iron shell 45 at its lower end being formed with the diametrically opposite feet 58 and 59 resting on the'tops of the ing secured together by bolts 60. For lthe purpose of holding the pipe 14 against the nozzle 12 to maintain a tight connection at the joint` 15, a bar 61 having adjusting screws 62 at its ends bearing on the lugs 63 and 64 on the posts 56 and 57 respectively engages the underside of the pipe 14 substantially in line with the nozzle 12. It will be seen that by screwing down on the screw 62 the bar 61 will be forced against the pipe 14 thereby holding it against the nozzle 12. It is the intention to make the bar 61 of such dimensions that it will bendand deflect before exerting such a force on the pipe connections as to break the same. This novel means of forming a joint and holding it tight, it will be observed, supports the parts in such a manner that they are not subjected to any tensile stress, thus permitting the use of the allow Duriron, previously mentioned. In a similar manner the pipe 22 is forced upward to maintain the joints 23 and 21 tight by a bar 65 having set screws 66 at its ends engaging lugs 67 on the supporting posts.

As previously described one end of the outlet pipe 34 has connection with the nozzle 33. The other end by means of a spherical joint 68 is joined to a short length of pipe 69 having an inclined ,ledge 7G at the upper end thereof forming a trough 471 around the joint. The lower end of this pipe 69 connects with t-he discharge main 72 by a spherical joint 73 likewise surroundedby a trough 74. The main 72 forms the discharge for the vapor outlet-s of all the containers and eX- tends by them in the manner illustrated in Figure l. This main is adjustably supported on the set screws 75, threaded through the bracket 76 secured to the cast iron shell` 45, as by means of the cap screws 77. F or the purpose of keeping the joints 35, 68 and 73y tight, without producing 'any tensile strainsl in the material of which the pipes are made, a bar 78, as shown, of channel section, is disposed above and parallel with the pipe 34 and has the two set screws 79 threaded through the same and bearing on the top ol said pipe. This bar is held against displacement in a vertical position by the tie rods 80 and 8l, the rod 80 being arranged between one end ofi-the bar 78 and the bracket 76 and the rod 81 being disposed between the opposite end of the bar 78 and the lug 82 at the upperl end of the cast iron shell 45. Thus by screwing down on the screws 79 the pipe 34 will be forced downward in a direction to keep the said joints tight and also hold the cover 31, ring 27 and shell l0 tightly together.

In order to expedite the evaporation of water from the acid the lead steam coils 83 may bedisposed within the container 10 being supported on the brackets 84 carried by the bottom 11. The inlet pipe of the coils is represented at 85 and the outlet pipe at 86. Each of these pipes passes through the upper head 31 and has a flange 87 at its upper end outside said head. This ange is clamped between two iron flanges 88 and 89 the latter flanges being drawn together by bolts 90 in the usual way. The flange 89 has a boss 91 which is forced against a gasket 92 surrounding the opening through which the pipe passes. The flange 88 has a nipple 93 which is connected to a T 94, the upper end of the T being closed by a plug 95 against which the screw 96 threaded through the bar 78a bears. Thus the flanges 89 are forced downward against the gaskets 92 by screwing down the screws 96. The other branch of the T 94 has the steam supply pipe 97 in the one instance and the condensed steam discharge pipe 98 in the other.

As' illustrated in Figure 1, the first containers through which the acid is passed may have the lead coils 83 and also the steam' jackets 46. The last containers/..11owever, which are illustrated by the right hand container of Figure 1, may have the lead coils omitted and the acid concentrated by the heat supplied from the steam in the jacket 46. Thus as the lead coils are not present in these latter containersl the degree of concentration may be carried beyond that at whichthe lead coils are actedup'on by the acid. In this manner a single apparatus is provided in which acid may be concentrated :trom a low to ahigh degree at one time.

` As illustrated in Figure 1, the right hand container which as stated shows' one of the end containers, in this instance the last container, it will be observed that the lead heating coils are omitted together with the connections for passing the pipes through the head 31. The acid is supplied to this container from the previous container through the pipe 22 having the trough 25 at the upper side thereof and this pipe is joined to the nozzle 12 by the spherical or ball joint 15, this joint being at a lower' elevation than the corresponding joint in the previous con tainer. The acid is discharged throughthe vertical outlet pipe which forms the continuation of the discharge nozzle 13. The latter nozzle is connected with t-he discharge pipe 20 by a ball joint 21 surrounded by the trough 19. This latter trough is disposed so that the spout 18 may discharge into the saine. The pipe 20 is held against the nozzle 13 by the parallel bars 65 carried on the lugs 67 on the supporting posts. The pipe 22 is held against the nozzle 12 by a bar 66 in the manner previously described.

In the operation of the apparatus, acid of a low degree of concentration is lfed in through the pipe 14 to the first container where it is subjected to the heat of the jacket and the coils which lboils oil' the water. The vapors thus given off pass through the vapor pipe 34 into the discharge main 72, one end of which is closed by the blank flange 99 and the other end of which is connected to the condenser which is connected to a vacuum pump or other means 'l'or maintaining aA vacuum in the acid main and the several containers. When the quantity of acid within the first container reaches thetop of the discharge pipe it will flow downward therethrough and along the pipe 22 to the next container filling up the latter in a similar manner. This will continue through the several containers until the container is reached which has no lead heating coil. y The apparatus will be designed so that the lead coils will be used in containers wherein the'acid is of suchY a degree of concentration that it will not injure the lead. Where the acid passes the degree of concentainers'will have the lead coils omitted, the

.concentration being carried on by the heat given off from the steam within the jackets. n the final container the acid is discharged downward through the nozzle 13 and pipe 20. i

It will be observed that the ball joints provided, not only form an automatic means for taking care of any disalignment due to expansion and contraction resulting from temperature changes, but-also permit some lee-way in assembling the parts. If the ball joints could be ground perfectly a non-leakable joint would be provided, but in practice they are likely to leak a little thereby permitting air to enter into the apparatus and interfere with the vacuum. In order to guard against this, the troughs have been provided surrounding the joints. A leak is quickly detected bypouring a little water into the troughs and noting if the level thereof is constant. If the water disappears, of course this action indicates leakage. To aid in forming tight joints a rsmall VquantityY of a suitable cement or granular materal may be placed in the troughs, still leaving enough space above the cement to test for leaks with water.

The lower shell 10 is subjected te greater temperature changes than the upper shell or ring 27 and the joint between these parts is provided` so that the material from which the parts are made will be relieved fromv the' stresses that would occur it the entire container were made integral.

Although a specific construction has been described, it is to be understood that the invention is not limited tothe details shown but includes changes and modifications which come within the scope of the appended claims.

Having thus described the invention what is claimed as new and desired to be se cured by Letters Patent is l. An acid concentrating apparatus comprising in combination, -an open ended container, a cover therefor, acid inlet andoutlet pip-es connected with the bottom of said container, a vapor outlet pipe connected to the top of the cover, all-said parts except the support being constructed of cast acid resisting material which is strong in compression but weak in tension, and means to secure said container, cover and pipes together without subjecting said parts to any tensional strains.

2. In acid concentrating apparatus, a cylindrical shell of cast racid resisting material, which is strong in compression but 'weak in tension, a second cylindrical shell surrounding the periphery of the first shell, said shells being constructed and arranged to form a steam jacket between them, and peripheral steam tight jointsat the ends of said jacket of substantially the same diameter as the periphery of the inner shell,where `by said latter shell is vsubjected to no substantial tensile. strain from the steam pressure. i

3. In acid concentrating tical cylindrical shell of cast acid resisting material, which is strong in compression but weak in tension, a second cylindrical shell surrounding the periphery of the first shell, said shells being constructed and arranged to forni a steam jacket between them, means to Support the, inner shell on the outer for removal axially including a peripheral shoulder at the upper end of the inner shell of slightly greaterdiameter than the bottom of said shell, and peripheral steam tight joints at the ends of said jacket of substantially the same diameter as the periphery of the inner shell, whereby said latter shell is subjected to no substantial tensile strain from the steam pressure. c

4. In acid concentrating apparatus, a shell of cast acid resisting material which lis strong in compression but weak in tension, having an outlet, an outlet pipe of like material, there being a joint between said pipe and outlet, and means for maintaining said joint tight without subjecting the material to tensile stresses including a member bearing aga-inst telpipe and supported independently of the s el.

5. In acid concentrating apparatus, a shell ot cast acid resisting material which is strong in compressionfbut weak in tension, having an outlet, an outlet pipe of like material, there being a joint between said pipe and outlet, and means separate from t-he pipe to force it toward the joint, thereby maintaining a tight joint without subjecting the acid resisting material to a tens-ile stress.

G. In cast acid concentrating apparatus, a shell of cast acid resisting material which is strong in compression but weak in tension, having an opening through its wall, a support for said shell, a pipe vof like material forming a passage registering with said opening, there being a joint therebetween, and means cooperating with the support to force the pipe toward` the shell, thereby maintaining a tight joint without subjecting the acid resisting material to a tensile stress.

7. In acid concentrating apparatus, a shell oi east acid resisting materialwhich is strong in compression but weak in tension a removable cover of like material for said shell, a support, and means cooperating with the support to force the cover toward the shell, thereby holding the cover tightly against the shell without producing tensional stresses in the said material.

8. In acid concentrating apparatus, .a series of connected containers of material vcapable of resisting concentrated acid comprising two groups, the containers of the first group having lead steam coils therein and the containers ofthe second group each having a steam jacket surrounding the same,

appara-tus, a verllO the first group adapted to concentrate the acid to a point short of aiiecting lead and the second group to concentrate the acid above this point.

9. In acid concentrating apparatus, a series of connected containers of material capable of withstanding concentrated. acid comprising two groups, the containers of the first group having lead steam coils therein and steam jacket-s surrounding the containers'and the second group each having the steam ackets only7 the yfirst group adapted to concentrate the acid to a point short of affecting lead and the second group to continue the vconcentration above this point.

10. In acid concentrating apparatus, a series of connected containers of material capable of resisting concentrated acid including two groups, one group having heating means disposed within the containers, and the other group having heating means disposed outside the containers, the rst group adapted to concentrate the acid to a point short of ali'ecting the iirst mentioned heating means and the second group to continue the concentration of the acid above this point. f

11. In acid concentrating apparatus, a container of cast acid resisting material which is strong in compression but weak in tension having an aperture through its wall, a pipe extending through said aperture, a gasket around said opening and means independent of the container to compress said gasket.

12. In acid concentrating apparatus, a cylindrical shell having one end closed and the other open, a second open ended shell forming a continuation of the iirst shell at its open end, a cover for the end of said second shell, all of said parts being constructed from a self-sustaining acid resisting material which is strong in compression but weak in tension and means acting on the shell and the top of the cover to draw said parts together axially and maintain the joints between them tight without subjecting said material to any tensional' strains.

13. In acid concentrating apparatus, a cylindrical shell having one end closedand the other open, a second open ended shell forming a continuation of the first shell at its open end, a cover for the end of said second shell, all of said parts being constructed from a self sustaining acid resisting material which is strong in compression but weak in tension, a support for the first shell and means coacting with said support and the top of said cover to draw the parts together axially and maintain the joints between them tight without subjecting the ma` terial to any tensional strains.

14. In acid concentrating apparatus, a. iirst pipe, a second pipe and an intermediate pipe having end to end ball or spherical joints with the other pipes, said pipes constructed of acid resisting material which is strong in compression but weak in tension, a member engaging the rst pipe, a member engaging the second pipe, and means to draw said members together t0 maintain said joints tight without subjecting the material to any tensional strains.

15. In acid concentrating apparatus, two pipes of acid resisting material which is strong in compression but weak in tension having an end to end joint, and members independent of but coacting with the pipes to force and hold them together to maintain said joint tight.

16. In acid concentrating apparatus, a container, a discharge main, a pipe connecting said container and main having spherical joints at its ends, a member independent of the rst pipe but coacting therewith, a second member independent of the main but coacting therewith, and means to draw said members together to maintain said joints tight without subjecting the parts to any tensional strains, said parts being constructed of acid resisting material which is strong in compression but weak in tension.

17. In acid concentrating apparatus, a vertical container of acid resisting material including two parts having an abutting horizontal joint, and a ledge carried by the lower part projecting above the joint and forming a trough around the same adapted to receive liquid to test the jointfor leaks.

18. In acid concentrating apparatus, a container, piping having a horizontal joint with said container and a ledge carried by the lower of the parts at the joint and projecting above the joint to form a trough around the same adapted to contain liquid to test the joint for leaks.

19. In acid concentrating apparatus, two v containers, a conduit of acid resisting material to conduct acid from one container to the other being jointed to said containers, troughs around said joints, and a trough extending lengthwise of said conduit to carry liquid from one of said joint troughs to the other.

In testimony whereof I affix my signature.

JOHN PATTEN. 

